Compare the plug shapes, voltage and frequency in Antigua and Barbuda and Guinea-Bissau, and find out which adapter you need before you travel.
Adapter required
Yes — coming from Antigua and Barbuda, you will need a travel adapter for Guinea-Bissau. Antigua and Barbuda uses Type A/Type B plugs, and Guinea-Bissau uses Type C/Type F, so the pin shapes will not fit any wall socket. The mains frequency is also different (60 Hz vs 50 Hz). This rarely matters for electronics but can affect motor-driven devices like clocks and shavers.
Antigua and Barbuda (home)
Guinea-Bissau (destination)
Electrical specifications in Guinea-Bissau
More about plugs in Guinea-Bissau
In Guinea-Bissau, the standard power plug is Type C and Type F. The country runs on 230 volts at 50 Hz. That means wall sockets in Guinea-Bissau can be one of 2 different shapes — Type C, Type F, and your plug needs to physically match the socket to fit.
Full Guinea-Bissau plug guide